1. Field of the Invention
The present invention relates to a concrete mixer which produces ready-mixed concrete by mixing materials such as gravel, aggregate, cement, water, admixture and so on.
2. Description of the Related Art
Conventionally, concrete is produced by: compounding water, cement, aggregate, various kinds of admixtures; and mixing these materials using a concrete mixer, while coarse aggregate such as gravel, crushed stones and sand, as well as fine aggregate such as fine sand are generally used as aggregate for the production of the above-described kind of concrete.
Meanwhile, since industrial wastes such as sludge, stone dust, refuse incineration ash, ceramic dust, glass dust, soil developed from a construction field and partially including waste paper or waste pulp are mostly disposed for land-filling, lack of land-fill sites as well as environmental pollution due to illegal dumping has become more serious than ever, and thus disposing the industrial wastes has become a serious problem in recent years. On the contrary, collecting sand from a river or a mountain, the sand being used as aggregate of concrete, has been subject to restrictions from the standpoints of nature-protection and environment conservation, while sea sand is not suitable for aggregate of concrete because sodium included therein causes concrete-deterioration. In this connection, attempts to use the ones which have conventionally had no alternative but to be disposed, such as sludge, stone dust, refuse incineration ash, ceramic dust, glass dust, soil developed from a construction field and partially including waste paper or waste pulp, as aggregate have been made, but these materials generally have large percentages of moisture content and large percentages of water absorption, and thus resistances thereof become large when agitated and mixed with the cement. This makes effective agitation and mixing difficult.
The present invention has been made to solve the above problem, and it is accordingly an object thereof to provide a concrete mixer which can enhance fluidities of raw materials of concrete when mixing the raw materials for a concrete structure so as to mix a mixture thereof reliably and effectively.